Method of installing a mount assembly in a multibeam cathode-ray tube

ABSTRACT

Method includes positioning a bulb assembly including a faceplate panel portion and a mount assembly including a multibeam electron-gun assembly in axial alignment on respective central longitudinal axes thereof. An orientation plane is then defined with reference to the structure of the electron-gun assembly, the orientation plane being at a prescribed angle with a reference plane through the apertures of at least two electron guns and parallel with the central longitudinal axis of the mount assembly. Then the bulb assembly and the mount assembly are rotated with respect to each other on the coincident longitudinal axes until the orientation plane is at a prescribed angle to one of the major or minor axes of the panel portion, thereby providing the desired rotational orientation between the bulb assembly and the mount assembly. Then, while maintaining the rotational orientation, the mount assembly is axially moved within the bulb assembly to a desired longitudinal location with respect to the faceplate panel portion. Then, the bulb assembly and mount assembly are permanently assembled.

United States Patent [1 1 Segro et al.

[451 Apr. 30, 1974 5/l968 Reinvall, Jr 29/25.l3

'Primary Examiner-Roy Lake Assistant ExaminerJ. W. Davie 0r Firm-G. H.Bmestle; L.

Attorney, Agent,

Greenspan ABSTRACT Method includes positioning a bulb assembly includinga faceplate panel portion and a mount assembly including a multibeamelectron-gun assembly in axial alignment on respective centrallongitudinal axes thereof. An orientation plane is then defined withreference to the structure of the electron-gun assembly, the orientationplane being at a prescribed angle with a reference plane through theapertures of at least two electron guns and parallel with the centrallongitudinal axis of the mount assembly. Then the bulb assembly and themount assembly are rotated with respect to each other on the coincidentlongitudinal axes until the orientation plane is at a prescribed angleto one of the major or minor axes of the panel portion, therebyproviding the desired rotational orientation between the bulb assemblyand the mount assembly. Then, while maintaining the rotationalorientation, the mount assembly is axially moved within the bulbassembly to a desired longitudinal location with respect to thefaceplate panel portion. Then, the bulb assembly and mount assembly arepermanently assembled.

9 Claims, 6 Drawing Figures mewus n.

nAPR 30 1974 Min 2 a PATENTEBAPR 30 I974 I I 11807 L 0 sum 3 or 4'PATENTEDAPRBO m I 3807 0 SHEET t UP 4 METHOD OF INSTALLING A MOUNTASSEMBLY IN A MULTIBEAM CATHODE-RAY TUBE BACKGROUND OF THE INVENTION Theinvention relates to an improved method of assembling a cathode-ray-tubebulb assembly and mount assembly, and particularly, but not exclusively,to a method of assembling an in-line multibeam electrongun assembly anda color-television-picture-tube bulb of the phosphor line screen type.

In a commercial color television picture tube of the apertured mask typehaving a three-color, viewingscreen structure, the viewing-screenstructure is photographically printed using light centers simulative ofthe position of the axis of each of the three electron guns in the finaltube. A mount assembly comprising three electron guns is subsequentlyinstalled in the tube. During the assembly of the electron-gun structurein the final tube, the axis of each electron gun must be oriented tocoincide with the light centers used to print the viewing-screenstructure within a desired rotational tolerance about the centrallongitudinal axis of the tube. In commercial color television picturetubes using dynamic convergence circuitry, a mount assembly having threeelectron guns in fixed orientation ordinarily must be positioned in thetube withinS degrees o f rotation. In a commercial color televisionpicture tub e using no dynamic convergence circuitry or simplifieddynamic convergence circuitry, a more accurate rotational positioning ofthe mount assembly is usually required.

In one prior method for assembling a multiple electron-gun structure,the alignment is accomplished by two separate assembly operations.During the mountassembly operation, the central longitudinal axis of theelectron-gun assembly is aligned with the stem axis, and the electronguns are rotationally aligned with the stem leads. Them, theelectron-gun assembly is attached to the stem leads with metal wires andribbons to form a mount assembly. In the subsequent mount-sealingoperation, the preassembled mount assembly is positioned and orientedwith respect to the bulb assembly and then sealed to the bulb assemblyon a sealing unit. The sealing unit holds and orients the bulb assemblyrotationally with respect to the major and minor axes and axially withrespect to the longitudinal axis of the bulb assembly. The sealingmachine also holds and orients the mount assembly axially with respectto the stem, and rotationally with respect to the stern leads. Althoughthis method of alignment is suitable for angular positioning of a mountassembly in some type cathoderay tubes, it is not sufficiently accuratefor others.

In the mount-sealing operation, the mount assembly is held rotationallywith the stem leads positioned within aligned holes on the sealingmachine. Since the holes include a clearance for loading and the mountassembly includes assembly tolerances, the rotational alignment of themount assembly with respect to the screen structure can only bemaintained within 3 of rotation. In addition, since the mount assemblyis preassembled and transported to the sealing machine, the fragilewires supporting the electron-gun assembly may be accidentally bent,thereby misaligning the electrongun assembly with the stem leads. Thismay result in angular misalignment of the electron-gun assembly when thestem leads are used to angularly align the bulb as sembly and the mountassembly. Furthermore, gauging of the amount of angular rotation of thepreassembled mount assembly after assembly and gauging of the amount ofangular rotation of the mount assembly in the assembled tube may berequired to ensure accurate rotational positioning of the electron gunswith respect to the viewing-screen structure in the finished tube.

SUMMARY OF THE INVENTION The novel method of assembling a bulb assemblyand a mount assembly for a cathode-ray tube is disclosed wherein themount assembly is oriented rotationally with reference to theelectron-gun structure instead of with reference to the stem leads. Thebulb assembly has a central longitudinal axis and includes asubstantially rectangularly-shaped faceplate portion having a major axisand a minor axis. The mount assembly has a cental longitudinal axis andincludes a multibeam electrongun assembly. The novel method includes 1.positioning a bulb assembly in a particular orientation with respect tothe central longitudinal axis thereof and one of the major or minor axesthereof,

2. positioning a mount assembly in a location spaced from the bulbassembly with the central longitudinal axis thereof coincident with thecentral longitudinal axis of the bulb assembly,

3. defining an orientation plane parallel to said axes through atleasttwo spaced points on the structure of the multibeam electron-gunassembly, the orientation plane being at a prescribed angle with areference plane through the apertures of at least two electron guns andparallel with the central longitudinal axis of the mount assembly,

f}. rotatingthe mount assembly and the bulb assembly on the coincidentlongitudinal axes with respect to each other until the orientation planeis at a prescribed angle with respect to one of the major or minor axes,thereby providing the desired rotational orientation between the bulbassembly and the electron-gun assembly,

5. then, while maintaining the rotational orientation, moving the mountassembly along the longitudinal axis to a desired longitudinal locationwith respect to the faceplate panel of the bulb assembly 6. and thepermanently fixing the mou r 1 t assembly to the bulb assembly. Y h

Assembling the mount assembly to the bulb assembly with directrotational alignment of the electron-gun structure with respect to oneof the major or minor axes of the faceplate portion eliminates anyaccumulation of error from preassembly of the mount assembly and fromclearance tolerances necessary for loading of the mount assembly on asealing unit. Also, since the rotational alignment is accomplishedimmediately prior to the sealing of the bulb assembly and the mountassem bly, accidental misalignment of the preassembled mount assemblydoes not affect the final tube alignment. In addition, additionalrequirements of prior gauging of the rotational alignment of apreassembled mount assembly and subsequent gauging of the finished tubeafter assembly of the mount may be eliminated. The novel method resultsin accurate rotational alignment of a multiple electron-gun assembly andbulb assembly, eliminates mount rotation scrap and provides economies inmanufacture. Furthermore, the accurately rotationally alignedelectron-gun assembly and bulb assembly result in a viewed picture ofimproved quality.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a broken-away sectionalelevational view of a bulb assembly and a mount assembly for acathoderay tube positioned on a head assembly for a main sealing unit.

FIG. 2 is a plan view of the head assembly and bulb assembly shown inFIG. 1.

FIG. 3 is an enlarged elevational view of a portion of FIG. 1 furtherillustrating a mount alignment apparatus.

FIG. 4 is a sectional plan view along section lines 4-4 of the apparatusshown in FIG. 3 showing an inline electron gun.

FIG. 5 is an alternative embodiment similar to that shown in FIG. 4showing a delta electron gun.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 illustrates a sectionalview of a bulb assembly 21 and a mount assembly 22 for a colortelevision picture tube of the apertured-mask type positioned on anapparatus known in the art as a main sealing unit 23 (only partiallyshown). The main sealing unit 23 is used to install the mount assembly22 in a precise location and orientation within the bulb assembly 21 tomake a color television picture tube assembly, as will be described inthe novel method.

COLOR TELEVISION PICTURE TUBE BULB ASSEMBLY A color television picturetube bulb assembly 21 comprises a glass envelope 24, athree-color-phosphor viewing screen structure 25, and an apertured-maskelectrode 26. The glass envelope 24 includes a faceplate portion 27,funnel portion 28, and a neck portion 29. The three-color-phosphorviewing screen structure 25 is supported on the inner surface of thefaceplate portion 27. The viewing-screen structure 25 is preferably aline-screen structure with phosphor lines extending parallel to theminor axis YY of the bulb assembly 21. The apertured-mask electrode 26is positioned in the envelope 24 in a predetermined spaced relationshipwith the viewing-screen structure 25. The apertured-mask electrode 26used with the line-screen structure 25 includes slot-shaped apertures(not shown). The slot-shaped apertures are positioned parallel to thephosphor lines of the viewing-screen structure 25.

The faceplate panel portion 27 is of a rectangular shape and includesthree reference surfaces 30a, 30b and 300 as shown in FIG. 2. Thereference surface 30a defines one of the small sides, and the referencesurfaces 30b and 30c define one of the large sides of therectangularly-ahaped faceplate portion 27. The reference surfaces alsodefine the position of a major axis XX and a minor axis YY for thefaceplate portion 27. In a VUR90 color television picture tube, therelationship of the position of the major and minor axes to thereference surfaces 30a, 30b and 300 is shown in FIG. 2. The referencesurface 30a is at an angle of 3 30 minutes clockwise with respect to anormal line to one of the short sides at the reference surface 30a, andthe reference surfaces 30b and 300 are at an angle of 4 clockwise andcounterclockwise respectively with respect to a normal line to one ofthe long sides at the reference surfaces 30b and 300, as shown in FIG.2. The major axis XX is a distance 31 of 5.332 inches from a line 32,which intersects the references surfaces 30b and 300 at a distance 33 ofl0.396 inches. The minor axis YY is a distance 34 of 6.396 inches froman intersection of the 3- 30-minute line, and the reference surface 30a.The minor axis YY is also perpendicular to the major axis XX. The bulbassembly 21 also includes a central longitudinal axis AA, which passescentrally through the neck portion 29 and the intersection of the majoraxis XX and minor axis YY.

COLOR TELEVISION PICTURE TUBE MOUNT ASSEMBLY The mount assembly 22comprises a stem assembly 35 and an electron-gun assembly 36. The stemassembly 35 includes a stem 37, exhaust tubulation 38, and stem leads39. The stem leads 39 are on a 0.600-inchdiameter pin circle and aremade of 0.040-inchdiameter wire. The outside diameter of the stem leadcircle is concentric with the central longitudinal axis Ar-A of themount assembly 22.

The electron-gun assembly 36 includes three electron guns and supportmeans between the stem leads 39 and the electron guns 40. An electrongun 40 includes a cathode 41, a control grid or G1 grid 42, a screengrid or G2 grid 43, a first accelerating and focusing grid or G3 grid44, a second accelerating and focusing grid or G4 grid 45, and a shieldcap 46. The various grids are mounted on glass support rods 47. Theshield cap 46 may also include bulb spacers 48 for centering the gunassembly within the neck portion 29.

In the 15VUR90 color television picture tube previously described, it ispreferred to use an in-line electron-gun assembly 36. An in-lineelectron-gun assembly 36 includes three electron guns in which theapertures of all of the electron guns are in a line. In one preferredin-line electron-gun assembly 36, such as described in US. patentapplication to R. H. Hughes, Ser. No. 217,758, dated Jan. 14, 1972, thevarious electrodes for all three electron guns are each formed in onepiece. For example, the G1 grid 42, G2 grid 43, G3 grid 44, and G4 gridare each one piece for the three electron guns.

In the in-line electron-gun assembly 36, the G3 grids are formed in theshape of a lower cup 49a and an upper cup 49b attached at their openends. Each of the cups includes three in-line apertures 50, one for eachof the three in-line electron guns 40. The cups are formed with sides 51parallel with the center-line 52 through the apertures within O.l ofrotation about a central longitudinal axis A A, of the mount assembly.The central longitudinal axis A,-A, of the mount assembly 22 is alsocoincident with the axis of the center electron gun. The sides of the G3grid cups 49a and 49b are a distance 53 of 0.190 inch from thecenterline 52 through the apertures, and the spacing between theapertures of the two end in-line electron guns is 0.562 inch.

SEALING UNIT It is preferred that a multihead rotary sealing unit 23(partially shown in FIG. 1) be used to practice the novel method. Therotary unit includes separate processing stations for loading,preheating, sealing, annealing and unloading. The sealing unit 23includes a rotatable head assembly 54 for each processing station. Thehead assembly 54 includes a support-frame assembly 55, a bulb-alignmentassembly 56, a neck chuck 57, a mount-support assembly 58, atubulation-lock assembly 59 and a sealing-fire assembly (schematicallyshown by arrow 60).

The support-frame assembly 55 includes a lower support 61 and an uppersupport 62. The lower support 61 is rotatably mounted on a main sealingunit 23 in bearings (not shown). The lower support 61 includes twovertical support rods 63. The upper support 62 is mounted at the top ofthe two support rods 63. The upper support 62 includes a bulb-supportmember 64 formed to hold the bulb assembly at the yoke reference line asshown in FIG. 1.

The bulb-alignment assembly 56 is also mounted on the upper support 62.The bulb-alignment assembly 56 includes a C-shaped support 65 havingthree reference units 66a, 66b, and 66c for orienting the bulb assembly21 and a bulb-clamp assembly 67 for retaining the bulb assembly 21against the three reference units.

The neck chuck 57 is mounted on the two vertical rods 63 as shown inFIG. 1. The neck chuck 57 comprises two jaws 68 and actuating means 69for equally moving the jaws.

The mount-support assembly 58 is mounted on the lower support 61. Themount-support assembly 58 includes a mount-pin support 70 and a mountpin 71. The mount-pin support is slidably mounted in the lower support61. The lower end of the mount-pin support 70 slides on a verticallydisplaced track (not shown) during indexing of the sealing unit 23.

An exhaust-tubulation lock 59 is mounted on the mount-support assembly58. The tubulation lock 59 includes three jaws and means for operatingthe jaws for equal movement thereof.

The main sealing unit 23 also includes means attached thereto foradjusting the rotational orientation of the mount assembly 22 and themajor axis XX of the bulb assembly 21 prior to the insertion of themount assembly 22 in the neck portion 29 of the bulb assembly 21. Theadjusting means 72 comprises a movable support frame 73, an alignmentmember 74, a gauging unit 75, and actuating means 76 (schematicallyshown in FIG. 3). The alignment member 74 includes one V- shaped surface77 and one flat surface 78. The gauging unit 75 includes two gauges 79attached to the alignment member 74 and a comparator unit 80.

The alignment member 74 is constructed to contact the two vertical rods63 when in measurement position. The two gauges 79 are mounted on thealignment member 74 on axes normal to a plane parallel to the verticalrods and centered on the central longitudinal axis A-A of the headassembly 54 as established by the engagement of the V-shaped surface 77with one of the vertical rods 63. In the preferred main sealing unit 23,the vertical rod spacing 81 is 4.500 inches. The normal line 82perpendicular to the plane of the rods is a distance 81a of 2.250 inchesfrom the center of the V- shaped surface 77. The gauges 79 are mounted adistance 83 apart of 0.562 inch and a distance 83a of 0.281 inch fromthe normal line 83. The normal line 83 passes through the centrallongitudinal axis AA of the head assembly 54.

The rotatable head assembly 54 is initially aligned with an alignmentgauge (not shown) to center the central longitudinal axis A A of thehead assembly respectively on each of the mount pin 71, the two verticalsupport rods 63, the neck chuck 57 and the bulbalignment assembly 56.The alignment gauge is also used to establish the location of thereference surfaces 60a, 60b and 600 to rotationally position the majoraxis XX parallel to the two support rods 63.

THE NOVEL METHOD A bulb assembly 21 is positioned in the head assembly54 on a bulb-support assembly 55 adapted to hold and orient the bulbassembly 21 with respect to the major and/or minor axes of thefaceplate-panel portion 27. The reference surfaces 30a, 30b, and 300 areengaged with the reference units 66a, 66b and 660 respectively, and thebulb clamp assembly 67 and the neck chuck 57 are operated to positionthe central longitudinal axis AA of the bulb assembly 21 coincident withthe central longitudinal axis A A of the head assembly 54.

The position of the bulb assembly 21 in the head assembly 54 establishesa reference plane 84 containing the longitudinal central axis AA of thebulb assembly 21, the plane of the two support rods 63, the major axisX-X, and the central longitudinal axis A A of the head assembly 54.

A mount assembly 22 is then positioned on a mount support assembly 58adapted to hold and orient the mount assembly 22 with the centrallongitudinal axis A,A of the mount assembly 22 coincident with thecentral longitudinal axis A-A of the bulb assembly 21 and centrallongitudinal axis A -A of the head assembly 54. The mount assembly 22 ispositioned on the mount pin 71 with the bottom of the stem 37substantially in full surface contact (not tilted) with the top surfaceof the mount pin 71. The exhaust tubulation 38 and the stem leads 39 areengaged within the mount pin 71 to substantially center the centrallongitudinal axis A A, of the mount assembly 22 coincident with thecentral longitudinal axis A A of the head assembly 54, and consequentlycoincident with the central longitudinal axis A--A of the bulb assembly21.

An orientation plane 85 is then defined with respect to the structure ofthe in-line electron-gun assembly 36. The orientation plane 85 is at aprescribed angle with the reference plane 84. The reference plane 84is-defined to pass through the apertures of at least two electron guns40 and is parallel with the central longitudinal axis A,-A, of the mountassembly 22. For an inline electron-gun assembly 36, it is preferredthat the orientation plane 85 is parallel to the reference plane 84.

In the mount assembly 22, the orientation plane 85 is defined byselecting two points 86a and 86b on the multiple in-line electron-gunstructure. The two points are spaced from each other and radially spacedaround the central longitudinal axis A,--A of the mount assembly 22. Thetwo points 86a and 86b are an equal distance from the reference plane 84and an equal radial distance from the aperture of the center in-lineelectron gun. In the in-line electron-gun assembly 36 previouslydescribed, the two points 86a and 86b are each on a line substantiallynormal to the reference plane 84 and located at the exterior surface ofthe upper G3 cup 49b. Since two of the G3 exterior surfaces are formedsubstantially parallel to the reference plane 84 as previouslydescribed, each of these surfaces contains the two reference pointswhich define the orientation plane 85.

The bulb assembly 21 and the mount assembly 22 are rotated with respectto each other on the coincident central longitudinal axes A-A and A A,respectively until the orientation plane 85 is substantially parallel tothe major axes.

The mount assembly 22 is first manually rotated until the referenceplane of the three in-line electron guns is nearly aligned with the twovertical rods 63, the blue electron gun is on the left, and thereference surfaces 30b and 300 are behind the central longitudinal axisA-A of the bulb assembly 21. The alignment means 72 is then operated toengage the alignment member 74 with the two vertical rods 63, and tomove the two gauges 79 into contact with the flat surface of the upperG3 cup 49b. The gauges 79 each contact the upper G3 cup 49b at one ofthe two points 86a and 86b previously described.

At this time, the mount assembly 22 is not precisely at the desiredrotational alignment. The readings of the two gauges 79 on a comparator80 will disclose any rotational misalignment. The two gauges 79 eachmeasure the actual dimension between the reference plane 84 and one ofthe two points 86a or 86b on the in-line electron-gun assembly 36. Thecomparator 80 permits balancing or equalizing of the two measureddimensions by rotating the electron-gun assembly 22, thereby determiningwhen the orientation plane 85 defined by the two contact points 86a and86b is aligned parallel to the reference plane 84. The mount assembly 22is then rotated until the measurements determined by the comparator forthe two gauges 79 are equal. This occurs when the two points 86a and 86bare each an equal distance from the reference plane 84. With the twopoints 86a and 86b an equal distance from the reference plane 84, thereference plane 84 is parallel to the major axis XX within less than 05of rotation about the coincident central longitudinal axes.

The mount assembly 22 is then maintained in the rotationally alignedposition by closing the tubulation lock 59. Closing the tubulation lock59 clamps the tubulation with respect to the mount pin 71 and thecentral longitudinal axis A A of the head assembly 54. The alignmentmeans 72 is then retracted to a standby position.

The mount assembly 22 is then moved along the central longitudinal axisA -A of the head assembly 54 to a desired longitudinal location withrespect to the faceplate portion 27 of the bulb assembly 21. The mountassembly 22 is guided within the neck portion 29 by bulb spacers 48which substantially maintain the center of the in-line electron-gunassembly on the central longitudinal axis A-A of the bulb assembly 21.At the desired longitudinal location, the stem 37 is sealed within theneck portion 29. The mount assembly 22 is moved into the neck portion 29during the cycle of the sealing machine 23 by the vertically displacedtrack previously described.

Finally,.the bulb assembly 21 and the mount assembly 22 are permanentlyfixed together. It is preferred that they are fixed by a seal betweenthe stem 37 and the neck portion 29. During the sealing, the lower partof the neck portion 29, known as the collet, is removed. The sealing ofthe bulb assembly 21 and the mount assembly 22 also includes preheatingand annealing of the glass, as is well known.

GENERAL CONSIDERATIONS AND ALTERNATIVES The novel method describes thatthe preferred location of the in-line electron-gun assembly is parallelto the major axis XX. The position may also be parallel to the minoraxis YY or at any angle between. This may be accomplished with the novelmethod with the two vertical rods 63 rotated or any angle between 0 and90 with respect to the bulb-alignment assembly.

Although the method describes positioning an inline electron-gunassembly having common electrodes, the novel method also may be used forother multiple electron-gun assemblies having separate individualelectrodes for each gun. For example, the novel method may be used on anin-line or delta electron gun having individual cylindrical electrodes.

Where a mount assembly having three individual cylindrical in-lineelectron guns is used, the two points which define the orientation planefor the electron-gun structure are each chosen to be at the point oftangency on each electron gun of a line tangent to at least two electronguns. It is preferred that the tangent points are selected with onepoint on each of the two end in-line electron guns. The cylindricalelectrodes must be round and concentric with the electron-gun apertureto permit the use of the novel method. Other gauging surfaces may alsobe selected or formed on the electrongun structure with the surfacesbeing precisely positioned a known dimension from the reference planeand the central longitudinal axis A A of the mount assembly 22 toestablish an orientation plane parallel or coincident with a first planethrough the apertures of the electron guns.

Where a delta electron-gun assembly 88 (shown in FIG. 5) having threecylindrical electron guns surrounding the theoretical center of themount assembly at separation isused, the two points are the points oftangency 89a and 89b on each of the two individual electron guns. Forthe delta electron-gun assembly 88, it is preferred that the blue gun beat the top or bottom of the viewing-screen structure. The tangent line90 defining the orientation plane 91 then contacts the red and greenindividual electron-gun structure, and a reference plane 92 is definedby the apertures of the individual red and green electron guns. For adelta electron-gun assembly 88, the reference plane 92 is not coincidentwith the plane of the major axis XX and the two vertical rods 63 as inthe in-line electron-gun assembly 36 previously described, but isparallel to the plane of the major axis XX and the vertical rods 63.Where the diameters of the two electron guns are different, theorientation plane 91 is tangent to the two electron guns and at a knownangle with respect to the reference plane 92 through the apertures ofthe two electron guns.

The multiple-head main sealing machine is described only as thepreferred apparatus for practicing the novel method. The novel methodmay also be practiced on a single-head sealing machine. Also, in eitherapparatus, the head may be held stationary and the tires rotated to makethe mount-bulb seal.

We claim:

1. A method of assembling a cathode-ray tube, said tube including a bulbassembly and a mount assembly, said bulb assembly having a centrallongitudinal axis and including a substantially rectangularly-shapedfaceplate panel having transverse major and minor axes, said mountassembly having a central longitudinal axis and including a multibeamelectron-gun assembly, said method comprising the steps of a.positioning said bulb assembly in a predetermined orientation,

b. positioning said mount assembly in a location spaced from said bulbassembly with the central longitudinal axis thereof coincident with saidcentral longitudinal axis of said bulb,

c. sensing the rotational position of said electron-gun assembly aboutsaid coincident longitudinal axes with respect to said positioned bulbassembly,

d. rotating said mount assembly about said coincident longitudinal axesuntil said electron-gun assembly is at a prescribed rotationalorientation with respect to said bulb assembly,

e. then, while maintaining said rotational orientation,

moving said mount assembly along said longitudinal axis to a desiredlongitudinal location with respect to the faceplate panel of said bulb,

f. and then permanently fixing said mount assembly to said bulbassembly.

2. The method defined in claim 1 wherein said step of defining anorientation plane comprises selecting two points on the structure of theelectron-gun assembly, each of said points spaced from each other andradially spaced around said central longitudinal axis of said mountassembly.

3. The method defined in claim 2 wherein said electron-gun assemblycomprises three in-line electron guns, said electron guns including atleast one common grid, said step comprising locating at least one pairof spaced points on said common grid, each of said points being equallydistant from said reference plane through the centers of said electronguns and of equal radial distance from the central electron gun.

4. The method defined in claim 2 wherein said electron-gun assemblycomprises three electron guns, each of said electron guns having atleast one cylindrical electrode, said step (c) comprising locating twopoints on an orientation plane tangent to two cylindrical electrodes,each of said two points being on one cylindrical electrode of adifferent electron gun.

5. The method defined in claim 3 wherein step ((1) comprises rotatingsaid mount assembly until said two points are each an equal distancefrom a plane of said coincident central longitudinal axes and one ofsaid major or minor axes.

6. The method defined in claim 2 wherein said reference plane of saidin-line electron-gun assembly is parallel to one of said major or minoraxes within less than 05 of rotation about said coincident centrallongitudinal axes.

7. The method defined in claim 1 wherein said tube includes a phosphorline screen and electron-gun assembly having three electron guns, saidphosphor lines being substantially parallel to one of said major orminor axes, said step ((1) comprising rotating said inline gun to arotational orientation whereby said reference plane is parallel to oneof said major or minor axes.

8. The method defined in claim 1 wherein maintain ing said rotationalorientation comprises clamping the exhaust tubulation of said mountassembly with respect to said central longitudinal axis of said mountassembly.

9. A method of assembling a color television picture tube, said tubeincluding a bulb assembly having a central longitudinal axis, arectangular-faceplate panel having a major and a minor axis, and a neckportion; and a mount assembly having a central longitudinal axis andincluding a multibeam electron-gun assembly and a stem assembly, saidmethod comprising the steps of a. positioning a bulb assembly on a bulbsupport adapted to hold said bulb in a predetermined orientation withrespect to the central longitudinal axis thereof and one of the major orminor axes thereof,

b. positioning said mount assembly on a rotatable mount support adaptedto hold said mount assembly with the central longitudinal axis of saidmount assembly coincident with said lingitudinal axis of said bulbassembly,

0. moving an alignment means into contact with said bulb support toorient said alignment means with respect to a plane through saidlongitudinal axis of said bulb assembly and one of said major or minoraxes,

d. sensing two preselected, spaced points on the structure of saidelectron-gun assembly, said points defining an orientation plane that isat a prescribed angle with a reference plane that passes through theapertures of at least two electron guns and is parallel to the centrallongitudinal axis of said mount assembly,

e. comparing the dimensions from said alignment means to each of saidtwo spaced points on said electron-gun assembly,

f. rotating said mount assembly in said mount support until each of saidmeasured dimensions is a desired dimension, whereby said reference planethrough said electron-gun apertures is substantially parallel to one ofsaid major or minor axes,

g. then, while maintaining said rotational orientation and coincidentlongitudinal axes, axially moving said mount assembly into said bulbassembly until the stem assembly is in the desired longitudinal positionwith respect to said faceplate panel,

h. and then sealing said stem assembly and said neck to form a colortelevision picture tube assembly.

UNITED STATES PATENT OFFICE @ETIFKQAT @F PATENTNO. 3 07 00 DATED 1 April30, 1974 INVENTOFHS) Jacob Francis Segro et: al

It is certified that error appears in the above-identified patent andthat said Letters Patent are hereby corrected as shown below:

Column 3, Line 58 change "ahaped" to -shaped.

Column 9, Line 26 change "'of defining an orientation plane" to (c)-;

Line 36 change "said" to a;

Line 48 change "of" to -through-;

Line 51 change '2 to 3-;

Line 56 change "1" to -3.

Column 10, Line 28 change "lingitudinal" to longitudinal-.

an flalfid this A ttest:

RUTH C. MASON C. MARSHALL DANN Alu'sling Officer (mnmissivm'r uj'lalenlsand Trademarks

1. A method of assembling a cathode-ray tube, said tube including a bulbassembly and a mount assembly, said bulb assembly having a centrallongitudinal axis and including a substantially rectangularly-shapedfaceplate panel having transverse major and minor axes, said mountassembly having a central longitudinal axis and including a multibeamelectron-gun assembly, said method comprising the steps of a.positioning said bulb assembly in a predetermined orientation, b.positioning said mount assembly in a location spaced from said bulbassembly with the central longitudinal axis thereof coincident with saidcentral longitudinal axis of said bulb, c. sensing the rotationalposition of said electron-gun assembly about said coincidentlongitudinal axes with respect to said positioned bulb assembly, d.rotating said mount assembly about said coincident longitudinal axesuntil said electron-gun assembly is at a prescribed rotationalorientation with respect to said bulb assembly, e. then, whilemaintaining said rotational orientation, moving said mount assemblyalong said longitudinal axis to a desired longitudinal location withrespect to the faceplate panel of said bulb, f. and then permanentlyfixing said mount assembly to said bulb assembly.
 2. The method definedin claim 1 wherein said step of defining an orientation plane comprisesselecting two points on the structure of the electron-gun assembly, eachof said points spaced from each other and radially spaced around saidcentral longitudinal axis of said mount assembly.
 3. The method definedin claim 2 wherein said electron-gun assembly comprises three in-lineelectron guns, said electron guns including at least one common grid,said step (c) comprising locating at least one pair of spaced points onsaid common grid, each of said points being equally distant from saidreference plane through the centers of said electron guns and of equalradial distance from the central electron gun.
 4. The method defined inclaim 2 wherein said electron-gun assembly comprises three electronguns, each of said electron guns having at least one cylindricalelectrode, said step (c) comprising locating two points on anorientation plane tangent to two cylindrical electrodes, each of saidtwo points being on one cylindrical electrode of a different electrongun.
 5. The method defined in claim 3 wherein step (d) comprisesrotating said mount assembly until said two points are each an equaldistance from a plane of said coincident central longitudinal axes andone of said major or minor axes.
 6. The method defined in claim 2wherein said reference plane of said in-line electron-gun assembly isparallel to one of said major or minor axes within less than 0.5* ofrotation about said coincident central longitudinal axes.
 7. The methoddefined in claim 1 wherein said tube includes a phosphor line screen andelectron-gun assembly having three electron guns, said phosphor linesbeing substantially parallel to one of said major or minor axes, saidstep (d) comprising rotating said in-line gun to a rotationalorientation whereby said reference plane is parallel to one of saidmAjor or minor axes.
 8. The method defined in claim 1 whereinmaintaining said rotational orientation comprises clamping the exhausttubulation of said mount assembly with respect to said centrallongitudinal axis of said mount assembly.
 9. A method of assembling acolor television picture tube, said tube including a bulb assemblyhaving a central longitudinal axis, a rectangular-faceplate panel havinga major and a minor axis, and a neck portion; and a mount assemblyhaving a central longitudinal axis and including a multibeamelectron-gun assembly and a stem assembly, said method comprising thesteps of a. positioning a bulb assembly on a bulb support adapted tohold said bulb in a predetermined orientation with respect to thecentral longitudinal axis thereof and one of the major or minor axesthereof, b. positioning said mount assembly on a rotatable mount supportadapted to hold said mount assembly with the central longitudinal axisof said mount assembly coincident with said lingitudinal axis of saidbulb assembly, c. moving an alignment means into contact with said bulbsupport to orient said alignment means with respect to a plane throughsaid longitudinal axis of said bulb assembly and one of said major orminor axes, d. sensing two preselected, spaced points on the structureof said electron-gun assembly, said points defining an orientation planethat is at a prescribed angle with a reference plane that passes throughthe apertures of at least two electron guns and is parallel to thecentral longitudinal axis of said mount assembly, e. comparing thedimensions from said alignment means to each of said two spaced pointson said electron-gun assembly, f. rotating said mount assembly in saidmount support until each of said measured dimensions is a desireddimension, whereby said reference plane through said electron-gunapertures is substantially parallel to one of said major or minor axes,g. then, while maintaining said rotational orientation and coincidentlongitudinal axes, axially moving said mount assembly into said bulbassembly until the stem assembly is in the desired longitudinal positionwith respect to said faceplate panel, h. and then sealing said stemassembly and said neck to form a color television picture tube assembly.